PRODUCT SPECIFICATIONSPart #: 0000-112553Fastener Type: Carriage BoltSize Description: 1/4"-20 x 1 1/2"Diameter/Nominal Size: 1/4"Length: 1 1/2"Head Diameter: 0.563-0.594"Head Height: 0.125-0.145"Neck Across Square/Diameter: 0.197-0.215"Neck Height: 0.105-0.135"Thread Pitch: 20Thread Pitch Type: CoarseThread Direction: RightSystem of Measurement: InchMaterial: Stainless Steel 18-8Finish: Plain Finish (No Plating)Average Piece Weight: 0.0230500 lbs.Carriage bolts are Ideal for use in square holes in wood-to-wood and wood-to-metal fastening; bolt has a square neck that prevents it from turning once screwed in. When trying to determine the length of the item, measure from just under the head of the bolt.